1. The Field of the Invention
The present invention relates to orthodontic brackets.
2. The Relevant Technology
Orthodontic brackets are secured to a patient""s teeth for use in selectively straightening the patient""s teeth. One type of orthodontic bracket known in the art includes a base having a slot formed thereon. The slot is configured to receive an archwire that extends between different teeth. A separate cover plate is removably attached to the base for use in securing the archwire to the base. One example of the above orthodontic bracket is disclosed in U.S. Pat. No. 4,712,999.
One object of the present invention is to develop an orthodontic bracket of the kind known in the prior art that is low-cost, simple to manufacture, and compact in construction.
The above and other objects of the present invention are satisfied by the features of the present invention as claimed herein and in particular by an inventive orthodontic bracket having a cover and base that are integrally connected together as a single piece. The inventive orthodontic bracket is low-cost and simple to manufacture. This is due in part to the fact that the orthodontic bracket comprises only one single component which does not have to be assembled. In addition, in one embodiment the inventive orthodontic bracket is made from only one single material, preferably plastic. Furthermore, the cover is integrally formed with the base so as to prevent unwanted separation.
Advantageous embodiments are described in the description, the dependent claims and the figures.
In accordance with a first embodiment, a hinge between the base and the cover can be formed by a reduction in the material cross-sections in the hinge region. The orthodontic bracket can be formed in a compact manner by the use of such hinges, which are also known as integral hinges or living hinges.
As an alternative to the integral one piece embodiment of the orthodontic bracket, the cover and the base can be connected to one another via a pluggable connection. This connection permits separation of the cover and the base without tools. The cover can, for example, be connected to the base via a grooved and tongued connection, for example in a dovetail form. It is possible in this way to put the cover onto the base via the pluggable connection, with the groove and tongue being formed so that a force fit is ensured with full insertion.
This last-mentioned embodiment has the advantage that a subsequent fastening of the cover to the base is possible. This can be advantageous for certain positions of the teeth in tight space conditions. It is also possible with this embodiment to remove the cover from the base in a simple manner and, where required, to replace it with a further cover which is merely placed onto the base. Such a procedure is advantageous when it is not or is no longer possible to pivot the cover around the base due to tight space conditions.
In accordance with a further advantageous embodiment, the orthodontic bracket includes a spring element which supports the closing and opening movement of the cover. This ensures that the cover is held in the open position by the spring element so that the opened cover does not hinder the insertion of the archwire. In one embodiment, the spring element is connected to the base and the cover via hinges. The hinges are preferably formed by a reduction of the material cross-sections in the hinge region. The resulting orthodontic bracket has a compact configuration despite the provision of the spring element. Low-cost manufacturing is ensured by the possibility of the bracket being made in one piece, for example, as an injection molded plastic part.
It is particularly advantageous if the spring element is fully integrated in the cover so that the bracket does not have any protruding parts or edges when in the closed state. The comfort in wear is fairly significantly increased in this way since no edges are present which could have an irritating effect for the patient in the mouth region.
In accordance with a further embodiment of the invention, the cover can have a recess which is open to the outside, but closed to the inside, and in which the spring element is completely received in the closed state of the cover. One advantage of this embodiment is that the spring element is completely integrated in the cover with respect to its outside so that a pleasant manner of wear results for the patient.
At the same time, however, the cover is completely closed in the region of the spring element. As a result, no remnants of food or the like can penetrate the inside of the cover.
In accordance with a further advantageous embodiment of the present invention, a reinforcement insert is provided on the base in the region of the slot. The reinforcement insert can be worked into the basic material of the bracket in the manufacturing process. This ensures that the forces acting in the region of the archwire are transferred without loss to the base and thus the tooth to be corrected. At the same time, the manufacturing costs are also reduced in this case since the bracket can be made of plastic in total and only the reinforcement part is made of a hard material, for example, metal.
The bracket in accordance with the invention is preferably formed in a self-ligating manner, i.e., the archwire is clamped between the cover and the base. It can be advantageous for this purpose for a plurality of locking recesses to be provided on the cover or the base in order to close the cover at different opening widths. Archwires having different cross-section sizes can be inserted into the slot in this way and be fixed there by closing the cover.
In one embodiment the cover is designed to cover the base along the whole outer contour and to extend preferably to the bottom of the base. This ensures that no contamination (food remnants) can enter into the inside of the bracket. Furthermore, the comfort in wear is considerably improved by a smooth, edge-free shape of the cover.
In accordance with a further aspect of the present invention, the invention comprises an orthodontic bracket kit. The kit includes at least one bracket having a cover integrally hinged to the base and a second, separate cover configured to attach to the base. The second cover does not have a shaped spring element, but rather locking elements for fastening the second cover to the base. In this embodiment, after the first integrally attached cover has been severed from the base, such as by use of a scalpel, the second cover can be put onto the base. Such a bracket kit allows the severing of the originally provided cover and the replacement of this cover with a separate cover. The second cover can be pressed onto the base in tight space conditions.
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.